/*
  ==============================================================================

   This file is part of the JUCE library - "Jules' Utility Class Extensions"
   Copyright 2004-10 by Raw Material Software Ltd.

  ------------------------------------------------------------------------------

   JUCE can be redistributed and/or modified under the terms of the GNU General
   Public License (Version 2), as published by the Free Software Foundation.
   A copy of the license is included in the JUCE distribution, or can be found
   online at www.gnu.org/licenses.

   JUCE is distributed in the hope that it will be useful, but WITHOUT ANY
   WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
   A PARTICULAR PURPOSE.  See the GNU General Public License for more details.

  ------------------------------------------------------------------------------

   To release a closed-source product which uses JUCE, commercial licenses are
   available: visit www.rawmaterialsoftware.com/juce for more information.

  ==============================================================================
*/

#include "../core/juce_StandardHeader.h"

BEGIN_JUCE_NAMESPACE

#include "juce_MD5.h"
#include "../io/files/juce_FileInputStream.h"
#include "../memory/juce_ScopedPointer.h"


//==============================================================================
MD5::MD5()
{
    zerostruct (result);
}

MD5::MD5 (const MD5& other)
{
    memcpy (result, other.result, sizeof (result));
}

MD5& MD5::operator= (const MD5& other)
{
    memcpy (result, other.result, sizeof (result));
    return *this;
}

//==============================================================================
MD5::MD5 (const MemoryBlock& data)
{
    ProcessContext context;
    context.processBlock (data.getData(), data.getSize());
    context.finish (result);
}

MD5::MD5 (const void* data, const size_t numBytes)
{
    ProcessContext context;
    context.processBlock (data, numBytes);
    context.finish (result);
}

MD5::MD5 (const String& text)
{
    ProcessContext context;

    const int len = text.length();
    const juce_wchar* const t = text;

    for (int i = 0; i < len; ++i)
    {
        // force the string into integer-sized unicode characters, to try to make it
        // get the same results on all platforms + compilers.
        uint32 unicodeChar = ByteOrder::swapIfBigEndian ((uint32) t[i]);

        context.processBlock (&unicodeChar, sizeof (unicodeChar));
    }

    context.finish (result);
}

void MD5::processStream (InputStream& input, int64 numBytesToRead)
{
    ProcessContext context;

    if (numBytesToRead < 0)
        numBytesToRead = std::numeric_limits<int64>::max();

    while (numBytesToRead > 0)
    {
        uint8 tempBuffer [512];
        const int bytesRead = input.read (tempBuffer, (int) jmin (numBytesToRead, (int64) sizeof (tempBuffer)));

        if (bytesRead <= 0)
            break;

        numBytesToRead -= bytesRead;

        context.processBlock (tempBuffer, bytesRead);
    }

    context.finish (result);
}

MD5::MD5 (InputStream& input, int64 numBytesToRead)
{
    processStream (input, numBytesToRead);
}

MD5::MD5 (const File& file)
{
    const ScopedPointer <FileInputStream> fin (file.createInputStream());

    if (fin != 0)
        processStream (*fin, -1);
    else
        zerostruct (result);
}

MD5::~MD5()
{
}

//==============================================================================
namespace MD5Functions
{
    void encode (void* const output, const void* const input, const int numBytes) throw()
    {
        for (int i = 0; i < (numBytes >> 2); ++i)
            static_cast<uint32*> (output)[i] = ByteOrder::swapIfBigEndian (static_cast<const uint32*> (input) [i]);
    }

    inline uint32 rotateLeft (const uint32 x, const uint32 n) throw()           { return (x << n) | (x >> (32 - n)); }

    inline uint32 F (const uint32 x, const uint32 y, const uint32 z) throw()    { return (x & y) | (~x & z); }
    inline uint32 G (const uint32 x, const uint32 y, const uint32 z) throw()    { return (x & z) | (y & ~z); }
    inline uint32 H (const uint32 x, const uint32 y, const uint32 z) throw()    { return x ^ y ^ z; }
    inline uint32 I (const uint32 x, const uint32 y, const uint32 z) throw()    { return y ^ (x | ~z); }

    void FF (uint32& a, const uint32 b, const uint32 c, const uint32 d, const uint32 x, const uint32 s, const uint32 ac) throw()
    {
        a += F (b, c, d) + x + ac;
        a = rotateLeft (a, s) + b;
    }

    void GG (uint32& a, const uint32 b, const uint32 c, const uint32 d, const uint32 x, const uint32 s, const uint32 ac) throw()
    {
        a += G (b, c, d) + x + ac;
        a = rotateLeft (a, s) + b;
    }

    void HH (uint32& a, const uint32 b, const uint32 c, const uint32 d, const uint32 x, const uint32 s, const uint32 ac) throw()
    {
        a += H (b, c, d) + x + ac;
        a = rotateLeft (a, s) + b;
    }

    void II (uint32& a, const uint32 b, const uint32 c, const uint32 d, const uint32 x, const uint32 s, const uint32 ac) throw()
    {
        a += I (b, c, d) + x + ac;
        a = rotateLeft (a, s) + b;
    }
}

//==============================================================================
MD5::ProcessContext::ProcessContext()
{
    state[0] = 0x67452301;
    state[1] = 0xefcdab89;
    state[2] = 0x98badcfe;
    state[3] = 0x10325476;

    count[0] = 0;
    count[1] = 0;
}

void MD5::ProcessContext::processBlock (const void* const data, const size_t dataSize)
{
    int bufferPos = ((count[0] >> 3) & 0x3F);

    count[0] += (uint32) (dataSize << 3);

    if (count[0] < ((uint32) dataSize << 3))
        count[1]++;

    count[1] += (uint32) (dataSize >> 29);

    const size_t spaceLeft = 64 - bufferPos;
    size_t i = 0;

    if (dataSize >= spaceLeft)
    {
        memcpy (buffer + bufferPos, data, spaceLeft);
        transform (buffer);

        for (i = spaceLeft; i + 64 <= dataSize; i += 64)
            transform (static_cast <const char*> (data) + i);

        bufferPos = 0;
    }

    memcpy (buffer + bufferPos, static_cast <const char*> (data) + i, dataSize - i);
}

//==============================================================================
void MD5::ProcessContext::finish (void* const result)
{
    unsigned char encodedLength[8];
    MD5Functions::encode (encodedLength, count, 8);

    // Pad out to 56 mod 64.
    const int index = (uint32) ((count[0] >> 3) & 0x3f);

    const int paddingLength = (index < 56) ? (56 - index)
                                           : (120 - index);

    uint8 paddingBuffer [64];
    zeromem (paddingBuffer, paddingLength);
    paddingBuffer [0] = 0x80;
    processBlock (paddingBuffer, paddingLength);

    processBlock (encodedLength, 8);

    MD5Functions::encode (result, state, 16);
    zerostruct (buffer);
}

void MD5::ProcessContext::transform (const void* const bufferToTransform)
{
    using namespace MD5Functions;

    uint32 a = state[0];
    uint32 b = state[1];
    uint32 c = state[2];
    uint32 d = state[3];
    uint32 x[16];

    encode (x, bufferToTransform, 64);

    enum Constants
    {
        S11 = 7, S12 = 12, S13 = 17, S14 = 22, S21 = 5, S22 = 9, S23 = 14, S24 = 20,
        S31 = 4, S32 = 11, S33 = 16, S34 = 23, S41 = 6, S42 = 10, S43 = 15, S44 = 21
    };

    FF (a, b, c, d, x[ 0], S11, 0xd76aa478);     FF (d, a, b, c, x[ 1], S12, 0xe8c7b756);
    FF (c, d, a, b, x[ 2], S13, 0x242070db);     FF (b, c, d, a, x[ 3], S14, 0xc1bdceee);
    FF (a, b, c, d, x[ 4], S11, 0xf57c0faf);     FF (d, a, b, c, x[ 5], S12, 0x4787c62a);
    FF (c, d, a, b, x[ 6], S13, 0xa8304613);     FF (b, c, d, a, x[ 7], S14, 0xfd469501);
    FF (a, b, c, d, x[ 8], S11, 0x698098d8);     FF (d, a, b, c, x[ 9], S12, 0x8b44f7af);
    FF (c, d, a, b, x[10], S13, 0xffff5bb1);     FF (b, c, d, a, x[11], S14, 0x895cd7be);
    FF (a, b, c, d, x[12], S11, 0x6b901122);     FF (d, a, b, c, x[13], S12, 0xfd987193);
    FF (c, d, a, b, x[14], S13, 0xa679438e);     FF (b, c, d, a, x[15], S14, 0x49b40821);

    GG (a, b, c, d, x[ 1], S21, 0xf61e2562);     GG (d, a, b, c, x[ 6], S22, 0xc040b340);
    GG (c, d, a, b, x[11], S23, 0x265e5a51);     GG (b, c, d, a, x[ 0], S24, 0xe9b6c7aa);
    GG (a, b, c, d, x[ 5], S21, 0xd62f105d);     GG (d, a, b, c, x[10], S22, 0x02441453);
    GG (c, d, a, b, x[15], S23, 0xd8a1e681);     GG (b, c, d, a, x[ 4], S24, 0xe7d3fbc8);
    GG (a, b, c, d, x[ 9], S21, 0x21e1cde6);     GG (d, a, b, c, x[14], S22, 0xc33707d6);
    GG (c, d, a, b, x[ 3], S23, 0xf4d50d87);     GG (b, c, d, a, x[ 8], S24, 0x455a14ed);
    GG (a, b, c, d, x[13], S21, 0xa9e3e905);     GG (d, a, b, c, x[ 2], S22, 0xfcefa3f8);
    GG (c, d, a, b, x[ 7], S23, 0x676f02d9);     GG (b, c, d, a, x[12], S24, 0x8d2a4c8a);

    HH (a, b, c, d, x[ 5], S31, 0xfffa3942);     HH (d, a, b, c, x[ 8], S32, 0x8771f681);
    HH (c, d, a, b, x[11], S33, 0x6d9d6122);     HH (b, c, d, a, x[14], S34, 0xfde5380c);
    HH (a, b, c, d, x[ 1], S31, 0xa4beea44);     HH (d, a, b, c, x[ 4], S32, 0x4bdecfa9);
    HH (c, d, a, b, x[ 7], S33, 0xf6bb4b60);     HH (b, c, d, a, x[10], S34, 0xbebfbc70);
    HH (a, b, c, d, x[13], S31, 0x289b7ec6);     HH (d, a, b, c, x[ 0], S32, 0xeaa127fa);
    HH (c, d, a, b, x[ 3], S33, 0xd4ef3085);     HH (b, c, d, a, x[ 6], S34, 0x04881d05);
    HH (a, b, c, d, x[ 9], S31, 0xd9d4d039);     HH (d, a, b, c, x[12], S32, 0xe6db99e5);
    HH (c, d, a, b, x[15], S33, 0x1fa27cf8);     HH (b, c, d, a, x[ 2], S34, 0xc4ac5665);

    II (a, b, c, d, x[ 0], S41, 0xf4292244);     II (d, a, b, c, x[ 7], S42, 0x432aff97);
    II (c, d, a, b, x[14], S43, 0xab9423a7);     II (b, c, d, a, x[ 5], S44, 0xfc93a039);
    II (a, b, c, d, x[12], S41, 0x655b59c3);     II (d, a, b, c, x[ 3], S42, 0x8f0ccc92);
    II (c, d, a, b, x[10], S43, 0xffeff47d);     II (b, c, d, a, x[ 1], S44, 0x85845dd1);
    II (a, b, c, d, x[ 8], S41, 0x6fa87e4f);     II (d, a, b, c, x[15], S42, 0xfe2ce6e0);
    II (c, d, a, b, x[ 6], S43, 0xa3014314);     II (b, c, d, a, x[13], S44, 0x4e0811a1);
    II (a, b, c, d, x[ 4], S41, 0xf7537e82);     II (d, a, b, c, x[11], S42, 0xbd3af235);
    II (c, d, a, b, x[ 2], S43, 0x2ad7d2bb);     II (b, c, d, a, x[ 9], S44, 0xeb86d391);

    state[0] += a;
    state[1] += b;
    state[2] += c;
    state[3] += d;

    zerostruct (x);
}

//==============================================================================
const MemoryBlock MD5::getRawChecksumData() const
{
    return MemoryBlock (result, sizeof (result));
}

const String MD5::toHexString() const
{
    return String::toHexString (result, sizeof (result), 0);
}

//==============================================================================
bool MD5::operator== (const MD5& other) const
{
    return memcmp (result, other.result, sizeof (result)) == 0;
}

bool MD5::operator!= (const MD5& other) const
{
    return ! operator== (other);
}

END_JUCE_NAMESPACE
